Display Device

ABSTRACT

The present invention provides a liquid crystal display device which exhibits the excellent wide viewing angle characteristic and the high-speed responsiveness. A pixel region includes a switching element which is operated in response to a scanning signal from a gate signal line, a pixel electrode to which a video signal from a drain signal line is supplied through a switching element, and a counter electrode which generates an electric field between the counter electrode and the pixel electrode. The pixel region is constituted of divided respective regions. In one region, the counter electrode made of a light-transmitting material which is formed on the center except for a slight periphery of the region below an insulation film and the pixel electrode which is constituted of a group of electrodes which extend in one direction and are arranged in parallel to each other in the direction which intersects one direction above the insulation film in a state that the group of electrodes are overlapped to the counter electrode are formed. In another region, the counter electrode which is constituted of a group of electrodes which extend in one direction and are arranged in parallel to each other in the direction which intersects one direction below the insulation layer and the pixel electrode which is constituted of a group of electrodes which extend in one direction and are arranged in parallel in the direction which intersects one direction above the insulation film and is arranged alternately with the counter electrode are formed.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of U.S. application Ser. No. 10/563,669,filed Jan. 6, 2006, the contents of which are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to a display device, and more particularlyto a liquid crystal display device.

BACKGROUND OF THE INVENTION

A liquid crystal display device referred to as a lateral electric fieldsystem is configured such that on a pixel region formed on aliquid-crystal-side surface of one substrate out of respectivesubstrates which are arranged to face each other with liquid crystaltherebetween, pixel electrodes and counter electrodes which generate anelectric field between the counter electrodes and the pixel electrodesare formed, and the liquid crystal is activated due to components of theelectric field substantially parallel to the substrate.

Further, in applying such a constitution to an active-matrix-type liquidcrystal display device, first of all, on the liquid-crystal-side surfaceof the above-mentioned one substrate, respective regions which aresurrounded by a plurality of gate signal lines which are arranged inparallel to each other and a plurality of drain signal lines which arearranged in parallel to each other in a state that drain signal linesintersect the gate signal lines are formed and these regions constitutethe above-mentioned pixel regions.

Further, each pixel region includes a thin film transistor which isoperated in response to a scanning signal from the gate signal line, theabove-mentioned pixel electrode to which a video signal is supplied fromthe drain signal line through the thin film transistor, and theabove-mentioned counter electrode to which a signal which becomes thereference with respect to the video signal is supplied.

Here, the pixel electrode and the counter electrode are respectivelyformed in a strip pattern which extends in one direction, wherein therespective electrodes are formed of two or more electrodes and theseelectrodes are usually arranged alternately. One example of such aconstitution is disclosed in U.S. Pat. No. 6,462,799.

Further, as a modification of the example, there has been known theconstitution in which one electrode out of the pixel electrode and thecounter electrode is formed in a planar shape and another electrode isformed in a linear shape, and another electrode is overlapped to oneelectrode by way of an insulation film. One example of the modificationis disclosed in U.S. Pat. No. 6,233,034.

DISCLOSURE OF THE INVENTION

The liquid crystal display device having such a constitution has acharacteristic to allow a viewer to clearly observe a display from thedirection which makes a large angle with respect to the verticaldirection of a display screen, that is, an excellent characteristic in awide viewing angle. However, the improvement of the high-speedresponsiveness has been also requested with respect to the liquidcrystal display device.

The present invention has been made under such circumstances and it isan object of the present invention to provide a liquid crystal displaydevice which exhibits a wide viewing angle characteristic and ahigh-speed responsiveness.

Further, it is another object of the present invention to provide adisplay device of a wide viewing angle and a high quality which includesboth of a transmissive region and a reflective region.

To briefly explain typical inventions among inventions disclosed in thisapplication, they are as follows.

(1) A liquid crystal display device is, for example, characterized inthat

on a liquid-crystal-side surface of one substrate out of substrateswhich are arranged to face each other with liquid crystal therebetween,a region which is surrounded by a plurality of gate signal lines whichare arranged in parallel to each other and a plurality of drain signallines which are arranged in parallel to each other in a state that thedrain signal lines intersect the gate signal lines defines a pixelregion,

the pixel region includes a switching element which is operated inresponse to a scanning signal from the gate signal line, a pixelelectrode to which a video signal from the drain signal line is suppliedthrough the switching element, and a counter electrode which generatesan electric field between the counter electrode and the pixel electrode,

the pixel region is constituted of divided respective regions, wherein

in one region, the counter electrode made of a light-transmittingmaterial which is formed on the center except for a slight periphery ofthe region below an insulation film and the pixel electrode which isconstituted of a group of electrodes which extend in one direction andare arranged in parallel to each other in the direction which intersectsone direction above the insulation film in a state that the group ofelectrodes are overlapped to the counter electrode are formed, and

in another region, the counter electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelto each other in the direction which intersects one direction below theinsulation layer and the pixel electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelin the direction which intersects one direction above the insulationfilm and is arranged alternately with the counter electrode are formed.

(2) A liquid crystal display device according to the present inventionis, for example, characterized in that

on a liquid-crystal-side surface of one substrate out of substrateswhich are arranged to face each other with liquid crystal therebetween,a region which is surrounded by a plurality of gate signal lines whichare arranged in parallel to each other and a plurality of drain signallines which are arranged in parallel to each other in a state that thedrain signal lines intersect the gate signal lines defines a pixelregion,

the pixel region includes a switching element which is operated inresponse to a scanning signal from the gate signal line, a pixelelectrode to which a video signal from the drain signal line is suppliedthrough the switching element, and a counter electrode which generatesan electric field between the counter electrode and the pixel electrode,

the pixel region is constituted of divided respective regions, wherein

in one region, the pixel electrode made of a light-transmitting materialwhich is formed on the center except for a slight periphery of theregion below an insulation film and the counter electrode which isconstituted of a group of electrodes which extend in one direction andare arranged in parallel to each other in the direction which intersectsone direction above the insulation film in a state that the group ofelectrodes are overlapped to the pixel electrode are formed,

in another region, the pixel electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelto each other in the direction which intersects one direction below theinsulation film and the counter electrode which is constituted of agroup of electrodes which extend in one direction and are arranged inparallel in the direction which intersects one direction above theinsulation film and is arranged alternately with the pixel electrode areformed, and

each counter electrode in each region is formed in a state that thecounter electrode covers the drain signal line.

(3) The liquid crystal display device according to the present inventionis, for example, on the premise of the constitution (2), characterizedin that the respective insulation films formed in the respective regionsare formed of a sequentially stacked body which is constituted of aprotective film made of an inorganic material and a protective film madeof an organic material, and the respective counter electrodes are formedof a light transmitting material.

(4) A liquid crystal display device is, for example, characterized inthat

on a liquid-crystal-side surface of one substrate out of substrateswhich are arranged to face each other with liquid crystal therebetween,a region which is surrounded by a plurality of gate signal lines whichare arranged in parallel to each other and a plurality of drain signallines which are arranged in parallel to each other in a state that thedrain signal lines intersect the gate signal lines defines a pixelregion,

the pixel region includes a switching element which is operated inresponse to a scanning signal from the gate signal line, a pixelelectrode to which a video signal from the drain signal line is suppliedthrough the switching element, and a counter electrode which generatesan electric field between the counter electrode and the pixel electrode,

the pixel region is constituted of divided respective regions, wherein

in one region, the counter electrode which is formed on the centerexcept for a slight periphery of the region below an insulation film andalso functions as a reflective electrode and the pixel electrode whichis constituted of a group of electrodes which extend in one directionand are arranged in parallel to each other in the direction whichintersects one direction above the insulation film in a state that thegroup of electrodes are overlapped to the counter electrode are formed,and

in another region, the counter electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelto each other in the direction which intersects one direction below theinsulation layer and the pixel electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelin the direction which intersects one direction above the insulationfilm and is arranged alternately with the counter electrode are formed.

(5) A liquid crystal display device is, for example, characterized inthat

on a liquid-crystal-side surface of one substrate out of substrateswhich are arranged to face each other with liquid crystal therebetween,a region which is surrounded by a plurality of gate signal lines whichare arranged in parallel to each other and a plurality of drain signallines which are arranged in parallel to each other in a state that thedrain signal lines intersect the gate signal lines defines a pixelregion,

the pixel region includes a switching element which is operated inresponse to a scanning signal from the gate signal line, a pixelelectrode to which a video signal from the drain signal line is suppliedthrough the switching element, and a counter electrode which generatesan electric field between the counter electrode and the pixel electrode,

the pixel region is constituted of divided respective regions, wherein

in one region, the counter electrode which is formed on the centerexcept for a slight periphery of the region below an insulation film andalso functions as a reflective electrode and the pixel electrode whichis constituted of a group of electrodes which extend in one directionand are arranged in parallel to each other in the direction whichintersects one direction above the insulation layer in a state that thegroup of electrodes are overlapped to the counter electrode are formed,

in another region, the counter electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelto each other in the direction which intersects one direction below theinsulation layer and the pixel electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelin the direction which intersects one direction above the insulationfilm and is arranged alternately with the counter electrode are formed,and

the insulation film has a larger thickness in another region than oneregion such that a film thickness of a liquid crystal layer in oneregion is approximately three times as large as a film thickness of aliquid crystal layer in another region.

(6) A liquid crystal display device according to the present inventionis, for example, on the premise of the constitution (5), characterizedin that the insulation film in one region is formed of a protective filmmade of an inorganic material, the insulation film in another region isformed of a sequentially stacked body consisting of a protective filmmade of an inorganic material and a protective film made of an organicmaterial, and at the same time, the counter electrode includes at leasta counter electrode which covers the drain signal line.

(7) A liquid crystal display device is, for example, characterized inthat

on a liquid-crystal-side surface of one substrate out of substrateswhich are arranged to face each other with liquid crystal therebetween,a region which is surrounded by a plurality of gate signal lines whichare arranged in parallel to each other and a plurality of drain signallines which are arranged in parallel to each other in a state that thedrain signal lines intersect the gate signal lines defines a pixelregion,

the pixel region includes a switching element which is operated inresponse to a scanning signal from the gate signal line, a pixelelectrode to which a video signal from the drain signal line is suppliedthrough the switching element, and a counter electrode which generatesan electric field between the counter electrode and the pixel electrode,

the pixel region is constituted of divided respective regions, wherein

in one region, the counter electrode which is formed on the centerexcept for a slight periphery of the region below an insulation film andalso functions as a reflective electrode and the pixel electrode whichis constituted of a group of electrodes which extend in one directionand are arranged in parallel to each other in the direction whichintersects one direction above the insulation layer in a state that thegroup of electrodes are overlapped to the counter electrode are formed,

in another region, the counter electrode which is constituted of a groupof electrodes which extend in one direction and are arranged in parallelto each other in the direction which intersects one direction below theinsulation layer and the pixel electrode which is constituted of a groupof electrodes which is extend in one direction and are arranged inparallel in the direction which intersects one direction above theinsulation film and is arranged alternately with the counter electrode,and

the insulation film has a layer thickness thereof in one region than thelayer thickness in another region.

(8) A liquid crystal display device according to the present inventionis, for example, on the premise of the constitution (7), characterizedin that the insulation film in another region is formed of a protectivefilm made of an inorganic material, and the insulation film in oneregion is formed of a sequentially stacked body consisting of aprotective film made of an inorganic material and a protective film madeof an organic material.

(9) A display device according to the present invention is, for example,characterized in that

on one substrate out of a pair of substrates which are arranged to faceeach other with liquid crystal therebetween, pixel electrodes andcounter electrodes are formed, wherein

the display device includes transmissive regions and reflective regions,and

a distance from the substrate to an uppermost layer electrode is setlarger in the transmissive regions than in the reflective regions, and aplanar distance between the uppermost layer electrodes is set larger inthe transmissive regions than in the reflective region.

(10) A display device according to the present invention is, forexample, on the premise of the constitution (9), characterized in thatthe display device includes a counter electrode made of a transparentconductor which extends is between the transmissive region and thereflective region, the display device includes a counter electrode madeof metal which is formed in the reflective region, and the displaydevice includes a pixel electrode formed of a transparent electrodewhich is formed on an uppermost layer and is spaced apart from thecounter electrode by way of an insulation film.

(11) A display device according to the present invention is, forexample, on the premise of the constitution (9), characterized in thatthe display device includes a pixel electrode made of a transparentconductor which extends between the transmissive region and thereflective region, the display device includes a pixel electrode made ofmetal which is formed in the reflective region, and the display deviceincludes a counter electrode formed of a transparent electrode which isformed on an uppermost layer and is spaced apart from the counterelectrode by way of an insulation film.

(12) A display device according to the present invention is, forexample, on the premise of the constitution (9), characterized in that aboundary between the transmissive region and the reflective regionexists in the inside of the display region.

(13) A display device according to the present invention is, forexample, on the premise of the constitution (12), characterized in thatthe initial orientation direction is substantially parallel to theextending direction of the boundary between the transmissive region andthe reflective region.

(14) A display device according to the present invention is, forexample, on the premise of the constitution (12), characterized in thatthe boundary between the transmissive region and the reflective regionis covered with the uppermost layer electrode thus providing a normallyblack mode.

(15) A display device according to the present invention is, forexample, on the premise of the constitution (14), characterized in thatthe uppermost layer electrode which covers the boundary between thetransmissive region and the reflective region sets atransmissive-region-side width thereof larger than areflective-region-side width thereof.

(16) A display device according to the present invention is, forexample, on the premise of the constitution (15), characterized in thatthe uppermost layer electrode which covers the boundary between thetransmissive region and the reflective region sets the width thereoflarger than a sum of a distance between the uppermost layer electrodesin the transmissive region and a distance between the uppermostelectrodes in the reflective region.

(17) A display device according to the present invention is, forexample, on the premise of the constitution (15), characterized in thatthe uppermost layer electrode which covers the boundary between thetransmissive region and the reflective region sets thetransmissive-region-side width thereof larger than a distance betweenthe electrodes in the transmissive region and sets thereflective-region-side width thereof larger than a distance between theelectrodes in the reflective region.

(18) A display device according to the present invention is, forexample, characterized in that

on one substrate out of a pair of substrates which are arranged to faceeach other with liquid crystal therebetween, pixel electrodes andcounter electrodes are formed, wherein each pixel includes a firstregion in which both of the pixel electrode and the counter electrodeextend in parallel linearly, and a second region in which one electrodeout of the pixel electrode and the is counter electrode is formedlinearly, and another electrode is formed in a planner shape and isoverlapped to one electrode by way of an insulation film.

(19) A display device according to the present invention is, forexample, on the premise of the constitution (18), characterized in thata distance between the linear electrodes differ between the first regionand the second region.

(20) A display device according to the present invention is, forexample, on the premise of the constitution (19), characterized in thatthe distance between the electrodes is set larger in the first regionthan in the second region.

According to the present invention, it is possible to obtain a displaydevice which exhibits excellent wide viewing angle characteristic andhigh-speed responsiveness.

Here, the present invention is not limited to the above-mentionedconstitutions and various modifications can be made without departingfrom a technical concept of the present invention.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 is a constitutional view showing one embodiment of a pixel of aliquid crystal display device according to the present invention.

FIG. 2 is a constitutional view showing one embodiment of the liquidcrystal display device according to the present invention.

FIG. 3 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 4 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 5 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 6 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 7 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 8 is a plan view showing another embodiment of the pixel of theliquid crystal display device according to the present invention.

FIG. 9 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 10 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 11 is a plan view showing another embodiment of the pixel of theliquid crystal display device according to the present invention.

FIG. 12 is a plan view showing another embodiment of the pixel of theliquid crystal display device according to the present invention.

FIG. 13 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 14 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 15 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 16 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 17 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 18 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 19 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 20 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 21 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 22 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 23 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 24 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 25 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

FIG. 26 is a constitutional view showing another embodiment of the pixelof the liquid crystal display device according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a mode for carrying out a liquid crystal display deviceaccording to the present invention is explained in conjunction withfollowing embodiments by reference to drawings.

Embodiment 1 Whole Constitution

FIG. 2 is a constitutional view showing one embodiment of the liquidcrystal display device according to the present invention. Although thedrawing is shown as an equivalent circuit, the drawing is depictedcorresponding to an actual geometrical arrangement.

The liquid crystal display device includes a pair of transparentsubstrates SUB 1, SUB 2 which are arranged to face each other withliquid crystal there between, wherein the liquid crystal is sealed by asealing material SL which also performs a function of fixing anothertransparent substrate SUB 2 to one transparent substrate SUB 1.

On a liquid-crystal-side surface of the above-mentioned one transparentsubstrate SUB 1, which is surrounded by the sealing material SL, gatesignal lines GL which extend in the x direction and are arranged inparallel in the y direction and drain signal lines DL which extend inthe y direction and are arranged in parallel in the x direction areformed.

Regions which are surrounded by the respective gate signal lines GL andthe respective drain signal lines DL constitute pixel regions and, atthe same time, a mass of these respective pixel regions arranged in amatrix array constitutes a liquid crystal display part AR.

Further, in each one of the respective pixel regions which are arrangedin parallel in the x direction, a common counter voltage signal line CLwhich runs in the inside of the respective pixel regions is formed. Thecounter voltage signal line CL constitutes a signal line for supplying avoltage which becomes the reference with respect to a video signal tocounter electrodes CT described later of the respective pixel regions.

In each pixel region, a thin film transistor TFT which is operated inresponse to the scanning signal from the one-side gate signal line GLand a pixel electrode PX to which the video signal from the one-sidedrain signal line DL is supplied through the thin film transistor TFTare formed.

The pixel electrode PX generates an electric field between the pixelelectrode PX and the counter electrode CT which is connected to thecounter voltage signal line CL and a light transmissivity of the liquidcrystal is controlled based on the electric field.

Respective one ends of the gate signal lines GL extend over the sealingmaterial SL and extending ends constitute terminals to which outputterminals of a vertical scanning drive circuit V are connected. Further,to input terminals of the vertical scanning drive circuit V, signalsfrom a printed circuit board which is arranged outside a liquid crystaldisplay panel are inputted.

The vertical scanning drive circuit V is constituted of a plurality ofsemiconductor devices, wherein a plurality of gate signal lines whichare arranged close to each other are formed into a group and onesemiconductor device is allocated to each group.

In the same manner, respective one ends of the drain signal lines DLextend over the sealing material SL and extending ends constituteterminals to which output terminals of a video signal drive circuit Heare connected. Further, to input terminals of the video signal drivecircuit He, signals from a printed circuit board which is arrangedoutside a liquid crystal display panel are inputted.

The video signal drive circuit He is also constituted of a plurality ofis semiconductor devices, wherein a plurality of drain signal lineswhich are arranged close to each other are formed into a group and onesemiconductor device is allocated to each group.

Further, the above-mentioned counter voltage signal lines CL each ofwhich is used in common in the respective pixel regions arranged inparallel in the x direction are connected in common at a right-side endportion in the drawing, the connection line extends over the sealingmaterial SL, and a terminal CLT is formed at the extending end. From theterminal CLT, a voltage which becomes the reference with respect to thevideo signal is supplied.

With respect to the respective gate signal lines GL, one gate signalline GL is sequentially selected in response to the scanning signal fromthe vertical scanning circuit V.

Further, to the respective drain signal lines DL, the video signal issupplied from the video signal drive circuit He in conformity with theselection timing of the gate signal lines GL.

Here, in the above-mentioned embodiment, the vertical scanning drivecircuit V and the video signal drive circuit He are formed ofsemiconductor devices which are mounted on the transparent substrate SUB1. However, the vertical scanning drive circuit V and the video signaldrive circuit He may be formed of so-called tape-carrier methodsemiconductor devices which are connected while striding over thetransparent substrate SUB 1 and the printed circuit board, for example.Further, when a semiconductor layer of the above-mentioned thin filmtransistor TFT is constituted of poly-crystal silicon (p-Si),semiconductor elements made of the above-mentioned crystal silicon maybe formed together with a wiring layer on a surface of the transparentsubstrate SUB 1.

<<Constitution of Pixel>>

FIG. 1( a) is a plan view showing one embodiment of the constitution ofthe above-mentioned pixel region further, a cross section taken along aline b-b in FIG. 1( a) is shown in FIG. 1( b) and a cross section takenalong a line c-c in FIG. 1( a) is shown in FIG. 1( c).

In the respective drawings, on a liquid-crystal-side surface of thetransparent substrate SUB 1, first of all, a pair of gate signal linesGL which extend in the x direction and are arranged in parallel in the ydirection are formed.

These gate signal lines GL surround a rectangular region together with apair of drain signal lines DL described later, wherein the region isconstituted as a pixel region.

Further, the pixel region is divided into two regions (an upper regionin the drawing being referred to as a region A and a lower region in thedrawing being referred to as a region B) which are defined by animaginary line which runs in the x direction in the drawing at asubstantially center of the pixel region.

Further, the counter voltage signal line CL is formed in parallel to thegate signal line GL, wherein the counter voltage signal line CL ispositioned at an upper portion on the region A side of the pixel region,for example.

Further, the counter voltage signal lines CL are formed in a pattern inwhich the counter voltage signal lines CL are formed in the inside ofthe pixel region in a state that the counter voltage signal lines CL arearranged close to the drain signal lines DL described later and extendalong the drain signal lines DL and, at the same time, the countervoltage signal lines CL are connected with each other in an upperportion of the region B of the pixel region.

That is, the counter voltage signal line CL is integrally formed at foursides in the region A of the pixel region and at three sides except fora lower-side portion in the region B.

Further, for example, one counter electrode CT which extends in the ydirection in the drawing at the substantially center of the region B ofthe pixel region is integrally formed with the counter voltage signalline CL.

In the region B, the counter voltage signal line CL which is arrangedclose to the drain signal line DL also functions as the counterelectrode CT thus forming three counter electrodes CT in total includingthe above-mentioned counter electrode CT.

Further, in the region A of the pixel region, a light-transmittingconductive film made of, for example, ITO (Indium Tin Oxide), ITZO(Indium Tin Zinc Oxide), IZO (Indium Zinc Oxide) or the like is formed,and four respective sides of the conductive film are overlapped to thecounter voltage signal line CL thus electrically connecting theconductive film with the counter voltage signal line CL.

The light transmitting conductive film is configured to function as acounter electrode CT in the region A.

On a surface of the transparent substrate SUB 1 on which the gate signallines GL and the counter voltage signal lines CL (counter electrodes CT)are formed in this manner, an insulation film GI which is made of SiN,for example, is formed in a state that the insulation film GI alsocovers the gate is signal lines GL and the counter voltage signal linesCL (counter electrodes).

The insulation film GI has a function of an interlayer insulation filmwith respect to the gate signal line GL and the counter voltage signalline CL in the region where the drain signal line DL described later isformed, a function of a gate insulation film with respect to the regionwhere the thin film transistor TFT described later is formed and afunction of a dielectric film in a region where a capacitive elementCstg described later is formed.

Further, on a surface of the insulation film GI, a semiconductor layerAS made of, for example, amorphous Si is formed in a state that thesemiconductor layer AS is overlapped to a portion of the gate signalline GL.

The semiconductor layer AS constitutes a semiconductor layer of the thinfilm transistor TFT, wherein by forming a drain electrode SD1 and asource electrode SD2 on an upper surface of the thin film transistorTFT, it is possible to constitute an MIS type transistor having theinversely-staggered structure which uses the portion of the gate signalline GL as a gate electrode.

Here, the above-mentioned drain electrode SD1 and the source electrodeSD2 are formed simultaneously at the time of forming the drain signalline DL.

That is, the drain signal lines DL which extend in the y direction andare arranged in parallel in the x direction are formed, portions of thedrain signal lines DL are extended to upper surfaces of thesemiconductor layers AS thus forming the drain electrodes SD1, and thesource electrodes SD2 are formed in a spaced-apart manner from the drainelectrodes SD1 by an amount corresponding to a channel length of thethin film transistor TFT.

The source electrode SD2 is extended from a surface of the semiconductorlayer AS to an upper surface of the pixel-region-side insulation film GIand the pixel electrode PX is integrally formed with the sourceelectrode SD2.

First of all, with respect to the pixel electrodes PX in the region B,two pixel electrodes PX are formed in a state that each pixel electrodePX is extended in the y direction and is arranged between the respectivecounter electrodes CT, and the pixel electrodes PX are connected witheach other on the counter voltage signal line CL which is formed on aboundary between the region B and the region A.

Due to such a constitution, in the region B of the pixel region, thecounter electrodes CT and the pixel electrodes PX are alternatelyformed, that is, in order of the counter electrode CT, the pixelelectrode PX, the counter electrode CT, the pixel electrode PX, thecounter electrode CT from one drain signal line DL side.

Further, with respect to the pixel electrode PX in the region A, thepixel electrode PX is formed of a group of electrodes consisting of aplurality of electrodes which extend in the y direction and are arrangedin parallel in the x direction in a state that the group of electrodesis overlapped to the counter electrode CT in the region, and therespective electrodes are integrally connected with each other on thecounter voltage signal line CL which is formed on the boundary betweenthe region A and the region B.

The number of pixel electrodes PX in the region A is set larger than thenumber of pixel electrodes PX in the region B. This is because that inthe region A, the pixel electrodes PX generate an electric field in aconcentrated manner between side portions (edge portions) of the pixelelectrodes PX and the counter electrode CT.

On the counter voltage signal line CL, a connecting portion of eachpixel electrode PX has a relatively large area and a capacitive elementCstg which uses the above-mentioned insulation film GI as a dielectricfilm is formed between the pixel electrode PX and the counter voltagesignal line CL at such a portion.

The capacitive element Cstg is configured to possess functions such as afunction of storing the video signal supplied to the pixel electrode PXfor a relatively long time and the like, for example.

On the surface of the transparent substrate SUB 1 on which the thin filmtransistors TFT, the drain signal lines DL, the drain electrodes SD1,the source electrodes SD2 and the pixel electrodes PX are formed in thismanner, a protective film PSV made of SiN, for example, is formed. Theprotective film PSV is a film which prevents the thin film transistorsTFT from directly coming into contact with the liquid crystal and isprovided for preventing the deterioration of the characteristic of thethin film transistor TFT.

Here, the above-mentioned protective film PSV may be, for example,formed of an organic material layer made of resin or a stacked bodywhich is constituted of an inorganic material layer and the organicmaterial layer. By adopting such a constitution, a surface of theprotective film PSV can be leveled and hence, it is possible tofavorably improve the rubbing property of an orientation film formed onthe protective film PSV.

Further, the orientation film (not shown in the drawing) is formed on anupper surface of the protective film PSV.

The orientation film is a film which is brought into direct contact withthe liquid crystal and determines the initial orientation direction ofmolecules of the liquid crystal by rubbing formed on the surface of theorientation film.

The liquid crystal display device having such a constitution includesthe region A and the region B in each pixel region, wherein in theregion A, right below the pixel electrodes PX by way of the insulationfilm GI, an electric field is generated between the pixel electrodes PXand the counter electrode CT including peripheries of the pixelelectrodes PX. In this case, a distance between the pixel electrodes PXand the counter electrode CT is set to an amount substantiallycorresponding to a thickness of the insulation film GI and hence, it ispossible to form the electric field having a relatively large intensitywhereby the high-speed responsiveness can be enhanced.

Here, the electric field which drives the liquid crystal is constitutedof a component substantially parallel to the transparent substrate SUB 1out of the electric field generated between the above-mentioned pixelelectrode PX and counter electrode CT. Accordingly, in this region A,the distance between each pixel electrode PX and the neighboring pixelelectrode PX is made relatively narrow thus increasing the electricfield of the component substantially parallel to the transparentsubstrate SUB 1 between the pixel electrode PX and the counter electrodeCT Accordingly, the number of pixel electrodes PX formed in the region Ais set larger than the number of pixel electrodes PX formed in theregion B.

On the other hand, in the pixel region B, the pixel electrodes PX andthe counter electrodes CT are alternately arranged by way of theabove-mentioned insulation film GI and the spaced-apart distance betweenthe pixel electrode PX and the counter electrode CT is relatively largeand hence, the electric field generated between the pixel electrode PXand the counter electrode CT contains a larger amount of componentsubstantially parallel to the transparent substrate SUB 1. This impliesthat the liquid crystal display device can possess the excellentwide-viewing-angle characteristic due to the nature of the behavior ofthe above-mentioned component of the liquid crystal.

In this manner, by controlling the number of electrodes in the regions Aand B, it is possible to allow the wide viewing angle, the high-speedresponsiveness and the high numerical aperture compatible with eachother.

Accordingly, the liquid crystal display device having such aconstitution can perform an image display which includes both of thewide viewing angle characteristic and the high-speed responsiveness.

Embodiment 2

FIG. 3 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 1.

The constitution which makes this embodiment different from theembodiment shown in FIG. 1 lies in that the pixel electrodes PX areformed on an upper surface of the protective film PSV in the region A ofthe pixel region.

In this case, the pixel PX electrodes are connected with each other incommon above the counter voltage signal line CL which runs at the centerof the pixel region in the x direction, and a portion of the connectingportion is electrically connected with the counter voltage signal lineCL via a through hole TH formed in the protective film PSV and theinsulation film GI in a penetrating manner.

Further, it is needless to say that the pixel electrodes PX may beformed of a non-light-transmitting material such as metal or a lighttransmitting material such as ITO or the like.

By adopting such a constitution, the liquid crystal display device canobtain the wide viewing angle characteristic and the high-speedresponsiveness.

Embodiment 3

FIG. 4 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 1.

The constitution which makes this embodiment different from theembodiment shown in FIG. 1 lies in that in the region A and the region Bof the pixel region, the respective pixel electrodes PX are formed on anupper surface of the protective film PSV.

Due to such a constitution, the pixel electrodes PX the number of whichdiffers largely between the regions, and are liable to easily produceetching residues can be formed on an uppermost layer and hence, it ispossible to reduce short-circuiting failures between the pixelelectrodes PX and other conductive layers such as the drain signal linesDL, the counter electrodes CT or the like.

In this case, one end of the pixel electrode PX which is arranged closeto the thin film transistor TFT is electrically connected with thesource electrode of the thin film transistor TFT via the through hole THformed in the protective film PSV and the insulation film GI in apenetrating manner.

Further, it is needless to say that the pixel electrodes PX may beformed of a non-light-transmitting material such as metal or a lighttransmitting material such as ITO or the like.

By adopting such a constitution, the liquid crystal display device canobtain the wide viewing angle characteristic and the high-speedresponsiveness.

Embodiment 4

FIG. 5 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 1.

The constitution which makes this embodiment different from theembodiment shown in FIG. 1 lies in that, first of all, the pixelelectrodes PX are formed on an upper surface of the insulation film GIand the counter electrodes CT are formed on an upper surface of theprotective film PSV.

That is, the pixel electrodes PX in the region B are integrally formedwith the source electrode D2 of the thin film transistor TFT and anelectric connection between the pixel electrode PX and the sourceelectrode SD2 is established in the boundary portion between the regionB and the region A. The pixel electrode PX in the region A is formed ina rectangular shape at a center portion of the region A except for aslight periphery of the region A, and the pixel electrode PX is formedof a light-transmitting conductive layer made of ITO or the like, forexample.

The protective film PSV is constituted of, for example, a sequentiallystacked body of a protective film PSV1 made of an inorganic materialsuch as SiN or the like and a protective film PSV2 made of an organicmaterial such as a resin.

The counter electrodes CT in the pixel region B are formed in a statethat each pixel electrode PX is arranged between the counter electrodesCT, while the counter electrode CT in the region A is constituted of agroup of electrodes formed of a large number of electrodes which extendin the y direction and are arranged in parallel in the x direction in astate that the counter electrode CT is overlapped to the pixel electrodePX.

Further, these respective counter electrodes CT are integrally formedwith the same material layer which is formed at a portion which coversthe gate signal line GL, at a portion which covers the drain signal lineDL and at a portion which defines the region A and the region B.

Here, the above-mentioned material layer which covers the drain signalline DL has a function of the counter electrode CT in the same manner asthe above-mentioned counter electrode CT and, at the same time, avoidsthe termination of lines of electric forces generated by an electricfield from the drain signal line DL to the neighboring pixel electrodePX by terminating the lines of electric forces. This is because that thetermination of the lines of electric forces to the pixel electrode PXadversely influences a display as noises.

Accordingly, the above-mentioned material layer which covers the drainsignal line DL has a center axis thereof substantially aligned with acenter axis of the drain signal line and has a width thereof set largerthan a width of the drain signal line.

Further, it is needless to say that the above-mentioned counterelectrodes CT may be formed of a non-light-transmitting material such asmetal or a light transmitting material such as ITO or the like.

By adopting such a constitution, the liquid crystal display device canobtain the wide viewing angle characteristic and the high-speedresponsiveness.

In this embodiment, by forming the counter electrodes CT on an uppermostlayer, it is possible to form the counter electrodes CT integrally andin a matrix array in the regions A, B and hence, the electricity supplyresistance can be reduced. Further, it is possible to optimize thecounter electrode CT on the drain signal line DL for every regionwithout influencing the numerical aperture and hence, the numericalaperture can be enhanced.

Embodiment 5

FIG. 6 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 1.

The constitution which makes this embodiment different from theembodiment shown in FIG. 1 lies in that the counter electrode CT in theregion A of the pixel region is replaced with a metal layer having afavorable light reflectance thus forming the region A into a lightreflection portion of the pixel region. That is, the above-mentionedcounter electrode CT is formed such that the counter electrode CT alsofunctions as a reflective electrode.

Incidentally, the region B forms a light transmitting portion using theconstitution substantially equal to the constitution shown in FIG. 1.

Here, the counter electrode CT in the region A may be integrally formedwith the counter voltage signal line CL and this embodiment adopts sucha constitution.

Further, in this embodiment, the respective pixel electrodes PX in theregion A and the region B of the pixel region are formed of electrodeswhich are formed in a state that the electrodes are overlapped to thecounter voltage signal line CL formed on the upper portion of the pixelregion and extend to the region A from another electrode of thecapacitive element Cstg, and electrodes which are formed in a state thatthe electrodes are overlapped to the counter voltage signal line CLwhich is formed on the upper portion of the pixel region and extend tothe region B from another electrode of the capacitive element Cstg.

Further, it is needless to say that the above-mentioned pixel electrodesPX may be formed of a non-light-transmitting material such as metal or alight transmitting material such as ITO or the like.

By adopting such a constitution, the liquid crystal display device canobtain the wide viewing angle characteristic and the high-speedresponsiveness.

In this embodiment, by forming the region A into the reflective region,it is possible to enhance both of the transmissivity and the reflectancecompared to the case in which the region B is formed of the reflectiveregion and hence, the present invention can simultaneously realize thehigh reflectance and the high numerical aperture which contradict toeach other at a glance.

Embodiment 6

FIG. 7 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 6.

The constitution which makes this embodiment different from theembodiment shown in FIG. 6 lies in that the pixel electrodes PX in theregion A of the pixel region and the pixel electrodes PX in the region Bof the pixel region are constituted of electrodes which are formed in astate that the electrodes extends to the region A from another electrodeof the capacitive element Cstg formed on the counter voltage signal lineCL formed on the boundary of the respective region in an overlappedmanner and electrodes which extend to the region B from anotherelectrode of the capacitive element Cstg.

Due to such a constitution, another electrode of the capacitive elementCstg is formed in a state that the capacitive element Cstg extends inthe x direction at the substantially center of the pixel region andfunctions as a light shielding film. Accordingly, it is possible toeliminate the mixing of lights in the respective displays of the displayregion A and the display region B.

Further, it is needless to say that the above-mentioned pixel electrodesPX may be formed of a non-light-transmitting material such as metal or alight transmitting material such as ITO or the like.

By adopting such a constitution, the liquid crystal display device canobtain the wide viewing angle characteristic and the high-speedresponsiveness.

Embodiment 7

FIG. 8 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 7.

The constitution which makes this embodiment different from theembodiment shown in FIG. 7 lies in that the region A which constitutesthe light reflective portion and the region B which constitutes thelight transmissive portion are formed in a reverse manner.

It is needless to say that such a constitution is also applicable to theEmbodiment 5

In the region A having the large number of pixel electrodes PX, ageneration ratio of etching residues between the pixel electrodes PXbecomes relatively high compared to the generation ratio of etchingresidues between the pixel electrodes PX in the region B. Further, thestructure in the vicinity of the thin film transistor TFT is complicatedand hence, the etching residues are liable to be easily generated.However, in this embodiment, since the reflective region is arranged onthe thin film transistor TFT side and hence, the residue generatingportion constitutes a reflective portion whereby there is no possibilitythat the reflectance is lowered and it is possible to ensure the stablereflectance.

Embodiment 8

FIG. 9 is a constitutional view showing another embodiment of the liquidcrystal display device according to the present invention andcorresponds to FIG. 6.

Compared with a case shown in FIG. 6, the region A of the pixel regionhas the substantially equal constitution. However, in the region B, aprotective film PSV2 is formed on an upper surface of the protectivefilm PSV1, and the counter electrodes CT are formed on an upper surfaceof the protective film PSV2.

To obviate a drawback attributed to the difference of lighttransmissivity caused by a fact that the light passes through the liquidcrystal layer twice in the region A which constitutes the lightreflective portion and passes through once in the region B whichconstitutes the light transmissive portion, a first-order birefringencemode is adopted with respect to the region B and a second-orderbirefringence mode is adopted with respect to the region A.

That is, in expressing the light transmissivity in the birefringencemode, in general, the light transmissivity T/T₀, when a uniaxialbirefringence medium is inserted between two polarizers which arearranged orthogonally from each other, is expressed by a followingformula (1).

T/T ₀=sin²(2X _(eff))·sin²(πd _(eff) ·Δn/λ)  (1)

Here, X_(eff) indicates an effective optical axis direction (an anglemade by an optical axis and a change transmission axis) of liquidcrystal composition, d_(eff) indicates an effective thickness of aliquid crystal composition layer having the birefringence, Δn indicatesthe reflectance anisotropy, and λ indicates a wavelength of light.

Here, the reason that the optical axis direction of the liquid crystalcomposition layer is set as the effective value is that the liquidcrystal molecules are fixed to an interface in the inside of an actualcell, all of liquid crystal molecules in the inside of the cell are notarranged in parallel and uniformly at the time of applying an electricfield to the liquid crystal, and the large deformation is generated inthe liquid crystal in the vicinity of the interface and hence, the lightaxis direction of the liquid crystal composition layer is treated as anapparent value when a uniform state is assumed as an average value withrespect to the light axis directions of the liquid crystal compositionlayer.

For example, to obtain the normally-closed characteristic in which adark state is obtained at the time of applying a low voltage and abright state is obtained at the time of applying a high voltage, as thearrangement of polarizers, a transmission axis (or an absorption axis)of one polarizer may be arranged substantially parallel to theorientation direction (a rubbing direction) of the liquid crystalmolecules and a transmission axis of another polarizer may be arrangedsubstantially perpendicular to the orientation direction of the liquidcrystal molecules.

Since X_(eff) in the above formula (1) is 0 at the time of applying noelectric field, T/T₀ becomes 0.

On the other hand, at the time of applying an electric field, a value ofX_(eff) is increased corresponding to a field strength and the value ofX_(eff) becomes maximum when the light axis direction is 450.

In this case, assuming that a wavelength of the light is 0.555 μm, forexample, to make the uniaxial birefringence medium become achromatic andhave the maximum transmissivity, the effective d_(eff)·Δn may be set to0.28 μm which is a ½ wavelength.

This implies that by setting the thickness of the liquid crystal layerin the region A which uses the second-order birefringence modeapproximately three times, that is approximately 2.5 times to 3.5 timesas large as the thickness of the liquid crystal layer in the region Bwhich uses the first-order birefringence, it is possible to optimize thedisplays of these respective regions.

Here, in FIG. 9, the counter electrode CT includes the counter electrodewhich is formed in a state that the counter electrode which covers thedrain signal line DL and has a function of terminating lines of electricforce generated by the electric field from the drain signal line DL asdescribed above. The counter electrode CT is electrically connected withthe counter electrode CT which is formed on the region A and is alsoformed on the region B side in a slightly extended manner via a throughhole formed in the protective film PSV2, PSV1 and the insulation film GIin a penetrating manner.

Embodiment 9

FIG. 10 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 9.

The constitution which makes this embodiment different from theembodiment shown in FIG. 9 lies in that, first of all, the protectivefilm PSV2 which is formed on the region B of the pixel region is alsoformed on the region A, and an opening is formed in a center portionexcept for a slight periphery of the protective film PSV2 of the regionA.

Further, the counter electrode formed on a surface of the protectivefilm PSV2 is formed also to cover the drain signal line DL and the gatesignal line GL on the region A side.

Due to such a constitution, the whole drain signal line DL is coveredwith the counter electrode CT having a shielding function thus achievingadvantageous effects such as the enhancement of the numerical apertureand the reduction of longitudinal smear.

Embodiment 10

FIG. 11 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 10 (a).

The constitution which makes this embodiment different from theembodiment shown in FIG. 10 (a) lies in that the counter electrode CTwhich is formed on an upper surface of the protective film PSV2 isconstituted of a non-light-transmitting material layer such as metal.

Due to such a constitution, it is possible to select a low resistancematerial as a material of the counter electrode CT and to directlysupply the counter voltage signal to the counter electrode and hence, itis possible to provide the constitution which has no through hole.

Further, it is possible to allow the counter electrode CT per se also toperform a function of a black matrix.

Embodiment 11

FIG. 12 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 11.

The constitution which makes this embodiment different from theembodiment shown in FIG. 11 lies in that the counter electrode CT whichis formed on the upper surface of the protective film PSV2 and thecounter electrode CT which is formed below the insulation film GI in theregion A are connected with each other via a through hole TH formed inthe protective film PSV2, the protective film PSV1 and the insulationfilm GI in a penetrating manner.

As shown in FIG. 11, by directly supplying the counter voltage signal tothe counter electrode CT formed on an upper surface of the protectivefilm PSV2, it is possible to obtain an advantageous effect that thecounter voltage signal line CL shown in FIG. 11 may not be formed.

Embodiment 12

FIG. 13 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 7.

The constitution which makes this embodiment different from theembodiment shown in FIG. 7 lies in that in the region A whichconstitutes a light reflective portion, the protective film PSV2 isformed on an upper surface of the protective film PSV1.

This constitution is provided for making a thickness of the liquidcrystal layer in the light reflective portion smaller than a thicknessof the light transmissive portion.

Since the light passes through the liquid crystal layer twice in thereflective portion, the layer thickness of the liquid crystal layer isdecreased correspondingly.

Accordingly, it is possible to perform a display of both regions A, Busing a first-order birefringence mode. In this case, it is preferableto set a thickness of the protective film PSV2 to ½ to 3/2 of thethickness of the liquid crystal layer. This is because that suchthickness relationship can maximize the respective transmissivities andreflectances of the regions A, B.

Embodiment 13

FIG. 14 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 13.

The constitution which makes this embodiment different from theembodiment shown in FIG. 13 lies in that on an upper surface of theprotective film PSV2 which is formed on the region A which constitutes alight reflective portion, the pixel electrodes PX are formed. The pixelelectrodes PX may be formed of a light-transmitting material layer.

In this case, the respective pixel electrodes PX are electricallyconnected with each other in the boundary portion between the region Aand the region B which constitutes a light transmitting portion and, atthe same time, the respective pixels are electrically connected with thepixel electrodes PX of the region B via a through hole formed in theprotective film PSV1.

Embodiment 14

FIG. 15 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 14.

The constitution which makes this embodiment different from theembodiment shown in FIG. 14 lies in that in the region A of the pixelregion, the pixel electrodes PX are formed on the same layer as thedrain signal lines DL and the counter electrodes CT are formed on asurface of the protective film PSV2.

In this case, the counter electrodes CT are formed in a state that thecounter electrodes CT also cover the drain signal lines DL and areconstituted of, for example, non-light-transmitting metal thusfunctioning also as a reflective electrode.

As a result, the counter electrodes CT in the region A and the counterelectrodes CT in the region B are arranged on layers different from eachother thus enabling the optimum setting of the counter electrodes CTwith respect to the corresponding pixel electrodes PX.

Further, in this embodiment, the counter electrodes CT on the protectivefilm PSV2 formed in the region A extend to a side wall surface of anopening portion formed in the protective film PSV2 in the region B andcover the side wall surface.

Since the counter electrodes CT are formed of a non-light-transmittingmaterial such as metal, for example, the counter electrodes CT functionas light shielding films whereby it is possible to suppress thegeneration of a reverse tilt domain on the side wall surface of theprotective film PSV2.

Embodiment 15

FIG. 16 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 6.

To compare the constitution of this embodiment with the constitution ofthe embodiment shown in FIG. 6, although the region A of the pixelregion has the substantially same constitution as the embodiment shownin FIG. 6, in the region B of the pixel region, the counter electrode CTin the portion is formed of a light transmitting material such as ITO,for example, in a center portion of the region except for a slightperiphery of the region, and the pixel electrodes PX are constituted bydirectly extending the respective pixel electrodes PX in the region A.

Embodiment 16

FIG. 17 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 16.

The constitution which makes this embodiment different from theembodiment shown in FIG. 16 lies in that although the protective filmPSV2 which is formed of an organic material is formed on the uppersurface of the protective film PSV1 and, at the same time, an opening isformed in a center portion of the region B of the pixel region exceptfor a slight periphery of the region B.

Embodiment 17

FIG. 18 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 17.

The constitution which makes this embodiment different from theembodiment shown in FIG. 17 lies in that the number of the pixelelectrodes PX in the region B of the pixel region is partiallydecreased.

Embodiment 18

FIG. 19 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 18.

The constitution which makes this embodiment different from theembodiment shown in FIG. 18 lies in that the number of the pixelelectrodes PX in the region B of the pixel region is set smaller thanthe number of the pixel electrodes PX in the region A of the pixelregion, the respective intervals of the pixel electrodes PX are setequal.

Embodiment 19

FIG. 20 is a constitutional view showing another embodiment of theliquid crystal display device according to the present invention andcorresponds to FIG. 19.

The constitution which makes this embodiment different from theembodiment shown in FIG. 19 lies in that, in the region A of the pixelregion, the pixel electrodes PX and the drain signal lines DL are formedon the same layer and, at the same timer the pixel electrodes PX areformed of a non-light-transmitting material such as metal.

Further, the protective film PSV2 which is made of an organic materialis formed on an upper surface of the protective film PSV1 and thecounter electrodes CT are formed on an upper surface of the protectivefilm PSV2. In this case, the counter electrodes CT are formed in a statethat the counter electrodes CT cover the drain signal lines DL in theregion and, further, the counter electrodes CT are made of a non-lighttransmitting material such as metal.

Embodiment 20

FIG. 21 is a view showing another embodiment of the liquid crystaldisplay device according to the present invention, wherein (a) is a planview of the pixel, and (b), (c), (d) are respectively schematiccross-sectional views taken along lines b-b, c-c and d-d in FIG. 21.

As shown in FIG. 21( b), a signal from the TFT is supplied through theSD and is connected to the pixel electrode PX formed on the insulationfilm PAS via a through hole TH. The pixel electrode PX is formed of atransparent electrode. As an example, ITO, IZO, ITZO and the like can beused and ITO is used in this embodiment.

Below the PX, a transparent counter electrode CTT is formed by way ofthe insulation film. The CTT is also formed of a transparent electrodeand the counter electrode CTT is formed of ITO in this embodiment.

In FIG. 21( c), a stepped portion is observed. The transparent counterelectrode CTT is formed on the substrate SUB and a metal counterelectrode CTM is formed on a portion thereof. On the CTT and the CTM,the pixel electrode PX is formed by way of an insulation film. Due tosuch a constitution, the pixel is constituted by having two regionstherein such that the CTM forming portion functions as a reflective typeand the CTM non-forming portion functions as a transmissive typeattributed by the CTT In the drawing, the reflective region is indicatedby R-3, the transmissive region is indicated by R-1, and an intermediateregion is indicated by R-2.

In the reflective region, the light which is incident on the liquidcrystal display device form the display screen side is reflected on theCTM and the light is irradiated to the display side again. Accordingly,the number of times that the light passes through the liquid crystallayer becomes twice compared to one time in the transmissive region.Accordingly, to maximize the light utilization efficiency, it isdesirable to set the layer thickness of the liquid crystal layer in thereflective region smaller than the layer thickness of the liquid crystallayer in the transmissive region. Accordingly, in this embodiment, bystacking the metal counter electrode CTM and the transparent counterelectrode CTT on the reflective region, the reflective region isconstituted such that the distance from the substrate SUB to the pixelelectrode PX is remote, that is, the thickness of the liquid crystallayer is decreased. Although the CTM is overlapped to the CTT from abovein the drawing, it is needless to say that the reverse constitution isalso applicable.

FIG. 21 (d) is a cross-sectional view of the vicinity of the videosignal line DL. The CTM is overlapped to an end portion of the CTT. Dueto such a constitution, the power supply resistance to the CTT made ofthe transparent electrode can be reduced by supplying the electricityfrom many directions using the CTM formed of the metal electrode. Thegate insulation film GI is overlapped to the CTT and the CTM, and thevideo signal line DL is formed on the gate insulation film GI. Further,an insulation film PAS is formed above the gate insulation film and thevideo signal line DL, and the pixel electrode PX is formed on theinsulation film PAS. The pixel electrode PX may be formed on the GI.

In FIG. 21 (a), a portion of the CTM is extended below the video signalline DL and is connected with the CTM between the pixels. That is, theportion of the CTM also functions as a common signal line CL.

The PX is, in the drawing, configured such that a plurality ofbent-shaped members have end portions thereof connected with each other.Accordingly, in plane, an electric field is generated between the CTT orthe CTM which is exposed between the PX and the PX thus performing adisplay. In this embodiment, the reason that the PX is bent is toachieve a so-called multi domain effect, wherein it is possible tobroaden a viewing angle by setting the directions of the electric fieldin plural numbers.

According to the present invention, it is possible to realize the liquidcrystal display device of a wide viewing angle which has thetransmissive region and the reflective region in combination.

Embodiment 21

FIG. 22 is a view which corresponds to FIG. 21 and shows therelationship between the pixel and the initial orientation direction.Symbol RUB indicates the initial orientation direction and assumes asubstantially same angle θ as absolute values with respect to twodirections of the bent electrodes and, at the same time, the directionswith respect to the bent electrodes and the RUB are made different fromeach other. Due to such a constitution, it is possible to maximize anadvantageous effect brought about by the multi domain.

Further, the pixel is formed such that an end portion of the CTM issubstantially parallel to the RUB. By adopting such a constitution, itis possible to smoothly perform the orientation treatment at a steppedportion thus realizing the enhancement of a contrast ratio.

Embodiment 22

FIG. 23 shows another embodiment corresponding to FIG. 21, wherein (b)is a schematic cross-sectional view taken along a line b-b in FIG. 23(a).

The distance between the pixel electrodes PX is set to L1 in thetransmissive region R-1 and L2 in the reflective region R-3. In thetransmissive region, the distance from the substrate SUB to the pixelelectrode PX is configured to be smaller than the corresponding distancein the reflective region. That is, the thickness of the liquid crystallayer in the transmissive region is set larger than the thickness of theliquid crystal layer in the reflective region. Due to such aconstitution, a drive voltage of the liquid crystal in the transmissiveregion becomes lower than the drive voltage of the liquid crystal in thereflective region. This is because that the brightness elevationcharacteristic with respect to the voltage of the liquid crystal layerdepends on the layer thickness of the liquid crystal layer. Accordingly,assuming that L1 and L2 are equal, the brightness characteristic withrespect to the voltage, that is, a so-called B-V curve largely differsbetween the transmissive portion and the reflective portion.

Accordingly, in this embodiment, the distance between the pixelelectrodes PX is set such that the L2 in the reflective region issmaller than the L1 in the transmissive region, that is, L1>L2.

Accordingly, by adjusting the field strength, it is possible to make theB-V curves in the transmissive portion and the reflective portion comeclose to each other whereby the liquid crystal display device which issuitable for both of transmission and reflection can be realized.

Embodiment 23

FIG. 24 is another embodiment corresponding to FIG. 21, wherein (b) is aschematic cross-sectional view taken along a line b-b in FIG. 24 (a).

An intermediate region R-2 portion belongs to neither one of thereflective region and the transmissive region and hence, becomes a causeof a domain. Accordingly, a stepped portion is covered with the pixelelectrode PX. Here, by adopting a normally black mode in which a blackdisplay is performed at the time of applying no voltage, even when thepixel electrode PX is constituted of a transparent electrode, a voltageabove the stepped portion assumes the same potential due to the pixelelectrode PX and hence, the generation of the domain can be preventedthus realizing a display with a high contrast ratio.

Further, this embodiment can also realize the prevention of the domainat the time of applying a voltage.

In this embodiment, with respect to the pixel electrode PX on thestepped portion, by setting a width thereof on a transmissive region R-1side as L3 and the width thereof on a reflective region R-3 side as L4,the relationship L3>L4 is established. Since the liquid crystal isdriven in the transmissive region with a voltage lower than a voltage inthe reflective region, the center of the pixel electrode PX on thestepped portion is displaced from the step thus arranging the pixelelectrode PX to satisfy the relationship L3>L4, it is possible tomaintain the stepped portion at a fixed potential effectively thussuppressing the generation of the domain.

Further, provided that a width L5 of the pixel electrode on the stepsatisfies the relationships L5>L1, L5>L2, it is desirable to make thewidth L5 to further satisfy the relationship L5>(L1+L2). This is becausethat it is possible to maintain the PX on the stepped portion at thefixed potential in a more stable manner.

Further, in the same manner, it is desirable that relationships L3>L1,L4>L2 are satisfied.

In this embodiment, as can be clearly understood from the drawing, anend portion of a metal counter electrode CTM is formed in a bent shapein the same manner as the pixel electrode PX. Due to such aconstitution, the stepped portion becomes parallel to the bent shape ofthe PX and hence, it is possible to maintain the above-mentionedrelationships in a stable manner within a wider range whereby the domaincan be suppressed.

Although this embodiment adopts the structure in which the pixelelectrode PX is formed above the counter electrode CTT or CTM, thisembodiment is also applicable to the structure in which the layerrelationship between the CTT and the PX is reversed. In such a case, itis sufficient that the transparent counter electrode CTT formed on thestepped portion satisfies the relationship similar to the pixelelectrode PX formed on a stepped portion as explained in thisembodiment.

Embodiment 24

FIG. 25 shows another embodiment corresponding to FIG. 21, wherein (b)is a schematic cross-sectional view taken along a line b-b in FIG. 25(a).

This embodiment is characterized in that the generation of the step isperformed using an insulation layer. Due to such a constitution, it ispossible to freely adjust the step such that a thickness of the stepbecomes equal to or more than a film thickness of the metal counterelectrode CTM and hence, it is possible to easily realize theoptimization of the transmissive region and the reflective region.

In this embodiment, the step is formed using the insulation film GI.Further, this embodiment obtains an advantageous effect that the stepformed by the insulation film can be formed independently from a shapeof the metal electrode. Accordingly, as shown in FIG. 25( a), an endportion of the GI is formed in a shape similar to the shape of the metalcounter electrode CTM shown in FIG. 24( a). Accordingly, it is possibleto adopt a concept of the embodiment 23 so as to obtain the advantageouseffect of the embodiment 23. Further, it is no more necessary to use theend portion of the metal counter electrode CTM in the formation of thestep and hence, the end portion of the metal counter electrode CTM canbe optimized for other purpose.

For example, FIG. 25( a) shows an example which aims at the enhancementof a yield ratio by arranging the end portion of the metal counterelectrode CTM parallel to the GL.

Further, FIG. 26 corresponds to FIG. 25( a) and shows an example inwhich the metal counter electrode CTM is used as a light shielding layerin the transmissive region, and by extending this region to thetransmissive region side than the stepped portion, the step portion isshielded from light thus eliminating the domain more efficiently.

It is needless to say that the above-mentioned respective embodimentsmay use the respective concepts in a single form or in combination. Thisis because that the explanation made in a separated manner forrespective embodiments is made for facilitating the explanation and theunderstanding of the invention by those who are skilled in the art.

Further, by constituting a monitor, a TV receiver set, a mobile phone orthe like using such a display device, it is possible to realize theenhancement of the display performance of the monitor, the TV receiverset or the mobile phone.

As has been clearly understood from the above-mentioned explanation,according to the liquid crystal display device of the present invention,it is possible to realize the display device which exhibits the wideviewing angle and the high-speed response. Further, it is possible torealize the high-quality display device which possesses the transmissiveregion and the reflective region in combination with the wide viewingangle.

INDUSTRIAL APPLICABILITY

The present invention is applicable to the display device as describedabove and can be put into practice in a display manufacturing industry,and more particularly, in a liquid crystal display device manufacturingindustry.

1-8. (canceled)
 9. A display device comprising: on one substrate out ofa pair of substrates which are arranged to face each other with liquidcrystal there between pixel electrodes and counter electrodes areformed; wherein video signals are supplied to each of the pixelelectrodes; wherein the counter electrode generates an electric fieldbetween the counter electrode and the pixel electrode; wherein thedisplay device includes transmissive regions and reflective regions;wherein an uppermost layer electrode is formed as an upper portion ofone of the counter electrode and the pixel electrode; wherein a distancefrom the substrate to the uppermost layer electrode is set larger in thereflective regions than in the transmissive regions, and wherein aplanar distance between the uppermost layer electrodes is set larger inthe transmissive regions than in the reflective regions.
 10. A displaydevice according to claim 9, wherein the display device includes acounter electrode made of a transparent conductor which extends betweenthe transmissive region and the reflective region, the display deviceincludes a counter electrode made of metal which is formed in thereflective region, and the display device includes a pixel electrodeformed of a transparent electrode which is formed on an uppermost layerand is spaced apart from the counter electrode by way of an insulationfilm.
 11. A display device according to claim 9, wherein the displaydevice includes a pixel electrode made of a transparent conductor whichextends between the transmissive region and the reflective region, thedisplay device includes a pixel electrode made of metal which is formedin the reflective region, and the display device includes a counterelectrode formed of a transparent electrode which is formed on anuppermost layer and is spaced apart from the pixel electrode by way ofan insulation film.
 12. A display device according to claim 9, wherein aboundary between the transmissive region and the reflective regionexists in the inside of the display region.
 13. A display deviceaccording to claim 12, wherein an initial orientation direction of theliquid crystal is substantially parallel to the extending direction ofthe boundary between the transmissive region and the reflective region.14. A display device according to claim 12, wherein the boundary betweenthe transmissive region and the reflective region is covered with theuppermost layer electrode.
 15. A display device according to claim 14,wherein the uppermost layer electrode which covers the boundary betweenthe transmissive region and the reflective region sets atransmissive-region-side width thereof larger than areflective-region-side width thereof.
 16. A display device according toclaim 15, wherein the uppermost layer electrode which covers theboundary between the transmissive region and the reflective region setsthe width thereof larger than a sum of a distance between the uppermostlayer electrodes in the transmissive region and a distance between theuppermost electrodes in the reflective region.
 17. A display deviceaccording to claim 15, wherein the uppermost layer electrode whichcovers the boundary between the transmissive region and the reflectiveregion sets the transmissive-region-side width thereof larger than adistance between the electrodes in the transmissive region and sets thereflective-region-side width thereof larger than a distance between theelectrodes in the reflective region. 18-20. (canceled)